The injury-plagued German was forced to retire from her opening singles match at the mixed teams tournament on Saturday due to a right knee problem.

Perth: Former top 10 player Andrea Petkovic's hopes of playing at the Australian Open have been dashed after she suffered a knee injury at the Hopman Cup.

The injury-plagued German was forced to retire from her opening singles match at the mixed teams tournament on Saturday due to a right knee problem, having just won the first set against Australian teenager Ashleigh Barty.

Petkovic was in tears as she left the court Saturday, revealing on Sunday that she had ruptured the meniscus in the knee for the second time in as many years.

She has withdrawn from the Hopman Cup, where she was partnering veteran Tommy Haas, and will return to Germany immediately for rehabilitation.

Petkovic hopes to only be sidelined for a month with her latest setback and said she was relieved the injury was not more serious -- she had the same knee reconstructed after tearing the anterior cruciate ligament (ACL) in 2008.

"It is a rupture of the medial meniscus," she said on Sunday.

"If they have to trim it then I will only be out for a month. If they have to sew it up again, it will take two to three months.

"Nonetheless, I am quite relieved it is not my ACL, I feared the worst. I hope I will be fine after a month."

Petkovic, 25, tore her ACL in her first game of the 2008 Australian Open.

She also suffered from ankle and back problems this year as her ranking slipped from a career-high ninth in 2011 to 126.

Due to her current low ranking, Petkovic would have needed to qualify for next month's Australian Open. She said she was disappointed to be ruled out of the year's first Grand Slam.

"It was the first Grand Slam at which I reached the quarter-finals and I had some great matches at Rod Laver Arena," she said.

Petkovic said she would draw inspiration from her Hopman Cup team-mate's injury battles, with Haas overcoming several serious setbacks during his career.

Hopman Cup organisers are seeking a replacement for Petkovic, with Croatian teenager Donna Vekic in the mix, which would rule Germany out of the tournament and reduce the rest of their matches to exhibition status.